Fretted electronic musical instrument



w A. DONAHUE FRETTED ELECTRONIC MUSICAL INSTRUMENT 2 Sheets-Sheet 1 Re mM 3 W3 m r/M r-- .3 w 1 w -i A, a L 2 u\=/m =k a v o o o V Z a f: n u iW 7. m m w a w May 21, 1957 Filed April 28, 1954 May 21, 1957 w. A.DONAHUE FRETTED ELECTRONIC MUSICAL INSTRUMENT '2 Sheets-Sheet 2 ffvENToi I n i j aamua mmmszmma a EIMEEEPGEEEEEQ 15a Filed April 28, 1954 60Willi am A 110 1 a]; ue

BY Mj m% ATTD RN EYE United States Patent FRETTED ELECTRONIC MUSICALINSTRUMENT William A. Donahue, Newark, N. J.

Application April 28, 1954, Serial No. 426,207

1 Claim. (Cl. 84-267) This invention relates to a musical instrument,and more particularly to an electrical finger board for musicalinstruments such as a guitar, banjo, mandolin, ukulele, zither or anelectrical guitar.

The object of the invention is to provide a musical instrument which hasa novel finger board whereby the instrument can be played with one handby pressing the string down instead of plucking or picking the string.

Another object of the invention is to provide a musical instrument whichcan be played either as a natural guitar or as an electric guitar withamplified sound, or as an electric guitar with electronic sounds.

A still further object of the invention is to provide an instrument foruse by persons who have lost one of their hands in accidents or in war.

Another object of the invention is to provide an instrument which can beplayed with one hand so as to permit the other hand to play anotherinstrument such as a drum, harmonica, piano or the like.

A still further object of the invention is to provide an electric guitarwhich can be played by either a person who is right or left handed andwherein the instrument is played simply by pressing the string down onthe contact to produce the note so that no picking of the string isnecessary.

A further object of the invention is to provide a musical instrumentwhich is extremely simple and inexpensive to manufacture.

Other objects and advantages will be apparent during the course of thefollowing description.

In the accompanying drawings, forming a part of this application, and inwhich like numerals are used to designate like parts throughout thesame:

Figure l is a plan view of the musical instrument, constructed accordingto the present invention.

Figure 2 is an enlarged top plan view of the finger board.

Figure 3 is a bottom plan view of the finger board.

Figure 4 is a sectional view taken on the line 4-4 of Figure 3.

Figure 5 is a sectional view taken on the line 55 of Figure 4.

Figure 6 is a wiring diagram showing the finger board and amplifier.

Figure 7 is a bottom plan view of a modified finger board wherein sixnotes can be played or produced at one time.

Figure 8 is a fragmentary wiring diagram for use with the finger boardof Figure 7.

Referring in detail to Figures 1 through 6 of the drawings, the numeral10 designates a guitar having a body member 11 and a finger board 12.The musical instrument 10 further includes a potentiometer 14, an on andoil switch 15, and a bridge 16.

Extending longitudinally along the top surface of the finger board 12 isa plurality of wires or strings 17, 18,

19, 20, 21, and 22, Figure 1. These strings 17 through 22 are adapted tobe manually pressed down instead of being plucked or picked and thesestrings may be made of any suitable conducting material such as steel. Atailpiece 24 is provided, and all six strings 17 through 22 are groundedto this tailpiece and also to a cable jack 25. The cable jack 25 iselectrically connected to the finger board and is also connected to thepotentiometer 14 and switch 15. The finger board itself is made of anon-conducting material such as wood or plastic. The opposite surface ofthe finger board 12 is provided with a plurality of longitudinallyextending grooves or recesses 23, Figures 3 and 4.

Extending upwardly from the finger board 12 is a plurality of frets 26which are adapted to be contacted by the strings 17 through 22 when thestrings are manually depressed. These frets 26 are held securely inplace on the finger board by suitable securing elements such as thebolts or rivets 27, and the bolts 27 include heads that are arranged inthe grooves 23. In Figure 2, the top of the finger boardis shown byitself with only the frets 26 in place. In Figure 3 the bottom of thefinger board is shown. A plurality of resistors 28 are positioned incertain of the grooves, and these resistors are electrically connectedto certain of the frets through the medium of conductors or wires 29.The grooves 23 are defined by wall sections 30, Figure 4, and each ofthese wall sections 30 are provided with a plurality of cutouts or slots31. A first set of jumper wires 32 are indicated by dotted lines inFigure 3, and these jumper wires 32 extend through certain of the slots31. A second set of jumper wires 33 extend through other of the slots31. The wires 33 are used to duplicate the note in the row of resistorsat the point where they are soldered to the contacts.

Referring to Figure 6 of the drawings, there is shown an amplifier foruse with the musical instrument of the present invention. The amplifierincludes a power supply 35 wherein A. C. current comes in through apower transformer 36 and this current is rectified by a rectifier tubewhich may be a 5Y3 type of tube. The voltage is stepped up from 13 plusthroughout all circuits.

There are three tubes 37, 38 and 39, and tube 37 is the audio-oscillatortube that sets up oscillation in a well known manner. In oscillatingtube 37, there is an oscillating frequency from plate 40 to grid 41 atan audio rate. The frequency of the audio signal that is oscillatingbetween the plate 40 and the grid 41 can be varied by varying the gridresistance.

The potentiometer 14 is merely for tuning the circuit.

-In the present invention, the grid resistance of the tube 37 is variedby manually pressing the strings 17 through 22 intocontact with thefrets 26 and this varies the frequency of the tube 37 itself by throwingin various resistances. Once the desired frequency is established in theoscillating tube 37, it is amplified through tubes 38 and 39, and theamplified sound is emitted through the loud-speaker 42. Thus, as theresistance is changed by pressing the strings 17 through 22 at diiferentplaces, the frequency of the signal is changed. There is furtherprovided a gaseous rectifier 43 which provides plate voltage to theoscillator tube 37. With the present invention, the resistance ischanged according to the desired note in order to vary the gridresistance or bias.

In use, and referring to Figure 6 of the drawings, any of the strings 17through 22 can be manually moved into engagement with any of the frets26 by pressing the strings downward. Each of these frets 26 correspondsto a musical note such as A, D, G, C, E, All, Di, and Gt and the like.The resistors 28 are connected in series with the frets. Thus, byengaging different notes or I quency pitch.

3 frets 26 with the strings, the grid resistance of the tube 37 will bevaried to thereby vary the frequency of the tube 37 itself sincedifferent numbers or amounts of resistors 28 will be thrown into thecircuit and these varying sounds will be amplified and emitted by theloudspeaker 42.

Referring to Figures 7 and'8 of the drawings,'there-is shown a modifiedarrangement wherein the finger board is indicated generally by thenumeral 44. Figure '7 shows the undersurface of the finger board 44which is provided with a plurality of spaced parallel wall sections 45that define grooves 46 therebetween. Frets Sfi may be secured to thefinger board in any suitable manner, *as for example by bolts orsecuring elements 47. 'Re'sistor's 48 are connected in series to thesecuring elements-47, and the resistors 43 are seated in'the grooves46.Itfwill be seen in'Figure 8 that lines'49 connect'certainofthe frets 50to a complete oscillating amplifying unit 60. Thus, thelines 49 areadapted to be each connected to an oscillating amplifier such as theamplifier shown in Figure 6. The numerals 51, 52, 53, 54, 55, and 56designate the strings of the musical instrument which are adapted to bemanually depressed to engage the frets 50.

With the arrangement shown in Figures 7 and 8, the user can play sixdifferent notes at one time which is now'an instrument such as an organ,piano, accordion or other instrument is played wherein more than onenote is played at one time in order to play a chord melody.

"However, in the arrangement shown in Figures 7 and 8 "six oscillatingamplifiers are required to produce the six 7 notes at one time, andthese six oscillating amplifiers are connected to the finger boardthrough the lines 49. Also,

in this modified arrangement if desired the user can play one note at atime so that if you press only one string tothe contact fret 50, you getone note. Similarly, if you press two different strings down you get twodifferent notes, and if you press three different strings down you getthree different notes so that all six strings can be actuated at onetime.

From the foregoing it is apparent that there has been provided a musicalinstrument such as an electric guitar 'notes together.

In Figures 7 and 8 six oscillating amplifier units are used and one unitis required for each row of contacts with the resistors between usingthe string above for ground. The jumper lines'32 connect the resistors28 in acontinuous line or as a series circuit. The other jumper lines 33are used to duplicate the same frequency pitched note to the othercontact frets that they are pumped and soldered to. All notes solderedto each jumper wire and contact fret must be the same fre- In thearrangement shown in Figures -1 through 6, only one note at a time canbe played on an instrument whereas in the arrangement shown in Figures71and 8 six different notes at one time can be played. In Figure 8 acommon ground line 57 is provided for all the six oscillatingamplifiers. The cable jack is grounded or Wires 33 interconnect adjacentnotes or'frets 'which are" similar. The printed letters in the blocksshown in "Figure6 are thenames of'theno'tes that each contact or fretrepresents and by starting at any contact, it will be 'EA, NO. in Figure8). controls, onefor each of the six oscillating units used in notedthat the jumper wires connect the same note in the contact blocks. Thewires are concealed in the body of the instrument and in the fingerboard 12. The potentiometer 14 is used for setting the frequency pitchof a note in the instrument. The cable jack 25 connects the oscillatingamplifier to the common ground tailpiece 24 and to the strings 17through 22 on the instrument. The line 53 goes to the bottom contact ofthe finger board as shown in Figure 6 or to all six bottom contacts ifan arrangement such as that shown in Figures 7 and 8 is used.

The finger board is made of a material that will not conduct electricityand can be made of any suitable material such as wood, plastic, orcomposition material. The upper surfaces of the frets 26 are rounded asshown in Figure 5 so that the guitar can be played in the usual mannerwithout using the electrical system. Then, by disconnecting theamplifier, the guitar can be played to .produce a straight naturalsound. Also, the instrument can be. played as an electric guitar withamplified sounds or with electronic sounds. The switch 15 can be used'tocut the amplifier on or off. The number of resistors used can bevaried as desired, and-also the values of these resistors can bechanged. The amount of resistors in the circuit determine the given notefrequency going into the oscillator tube 37 and the arrangement of theoscillating units can be varied as desired.

Without any electrical system and using the present invention it isnecessary that the strings be first pressed to the frets and plucked toproduce the sounds. With applicants finger board and oscillatingamplifier, it is only necessary to press the string to the contact fretand the note will be produced without plucking the string. As long asthe string is held to the contact frets the notes will keep soundingout, and this is only possible with the finger board of the presentinvention, since in other instruments the sound dies away afterplucking.

There are two potentiometers shown in Figure 6, and one of thepotentiometers is used to tune the 440 cycles the numeral 61 and is usedas a volume control for the oscillating amplifier in Figure 6.

In Figures 7 and 8 there are twelve potentiometers because there are sixindividual strings and six oscillating amplifier units. Six of thesepotentiometers are used to tune the bottom-most note of the six strings(A D G C The other six are volume the Figures 7 and 8 system. Thesepotentiometers that are used to tune the above notes may be in eitherthe instrument or placed in the oscillating amplifier cabinet ifdesired, since by placing them in the cabinet they will be out of theWay and will not be knocked or bumped. In Figure 6, preferably the onepotentiometer used to tune the A note would be most conveniently placedin the in tiometers for the Figures 7 and 8 system, preferably thesepotentiometers are placed in the oscillating amplifier cabinet so thatthe instrument can be tuned from the cabinet without fear of hitting thepotentiometers and knocking the six units out of tune.

The finger board may be secured to the body member by various methodssuch as by using screws which go through the finger board 12 at thepoints indicated by the numeral 62 and these screws may go into the bodymember 11. These screws hold the finger board in the correct positionand may also act as position marks to indicate the first, third, fifth,seventh, ninth, twelfth, fifteenth and seventeenth positions. Also, thefinger board can be glued to body member.

The theory and functioning of the system shown in Figures 7 and 8 is thesame as that shown in Figure 6 broadly. Thus, the same components thatare used in Figure 6 are also used in Figures 7 and 8. Figure 6 showsone complete circuit of components which includes the finger board withforty-one resistors in series, one single pole single throw switch 15,one potentiometer 14, one oscillator-amplifier 63, one speaker 42, onetailpiece 24 with the six strings 17, 18, 19, 20, 21 and 22 grounded toit. The Figure 6 system makes it possible to play any one of forty-twonotes but only one note can be played at a time. The jumper wires 32connect the first extreme right row of contacts and resistors with thatof the second, third, fourth, fifth and sixth rows.

In Figures 7 and 8 there must be six complete and separate circuits andeach of these six circuits are the same as the one complete circuit ofFigure 6. With the set-up shown in Figures 7 and 8 a person can play onenote, two notes, three notes, four, five or six notes at a timedepending upon how many strings are pressed to the contact frets 50.Also, any of the six strings can be cut out from playing electronicallyby using a single pole single throw switch and then the strings willplay or sound out with the amplified tone of the guitar to provide anovel effect and tricky efiects can be produced with the tone and colorcontrols of each circuit. In other words, the simulated sounds of sixdifferent instruments playing at one time can be produced. In Figure 6the numeral 63 designates the complete oscillator and amplifier circuit.Figure 6 requires one of these oscillator and amplifier circuits 63while Figures 7 and 8 require six of these same units.

In Figure 6 one oscillator-amplifier 63 is used to produce all theindividual notes possible on the finger board because the finger boardis so wired that only one note can be played at a time. Thus, if onlyone note can be played at a time only one oscillator-amplifier toproduce this one note is required. Further, no matter how many timesthis note is changed to a different note, there will still only be heardone note at a time. For example if a piano is played with one finger, itcan be played as fast as possible but still only one note can be heardand this one note is produced each time the key is struck with the onefinger and that idea is the same as shown in Figure 6. Thus, every noteon the finger board can be played but only one at a time. However, inFigures 7 and 8, more than one note can be produced at a time and inFigures 7 and 8 the finger board is broken up into six individualsections and each section will take care of eighteen individual notes.To each section of eighteen notes there is connected oneoscillator-amplifier to produce any one of the selected notes out of theeighteen. Thus, in Figure 7 there are six rows of resistors but thereare no jumper wires in the Figure 7 set-up. To each row of resistorsthere is connected one oscillatoramplifier to produce any of the notesin that particular row and if a string is pressed down and makes conatctwith the fret in a particular row, then the signal goes through theresistors in that row and to the corresponding amplifier and then outthrough the speaker such as the speaker 60. In Figures 7 and 8 there aresix complete individual units built into one general unit and each unitcomprises one string, eighteen contact frets, seventeen resistors, oneOn and Ofi switch, one potentiometer to adjust the pitch of thebottom-most note, and one oscillating amplifier with speaker. There aresix of these units, one for each of the rows of resistors in Figure 7.

The wires 33 interconnect adjacent notes or frets. It is to beunderstood that the person using the present invention need not buy anew amplifier since the persons present amplifier can be converted withthe addition of two or more tubes, one transformer, a few resistors andcondensers. With the addition of these parts the persons amplifier willbe able to play the instrument of the present invention through it and aconversion unit can be sold cheaply and with such a conversion unit anypublic address system or amplifier can be used. If a person does notwant tone and color ranges, a conversion unit can be provided at a verycheap price in other words a persons present amplifier can be veryeasily and cheaply converted so that it will use the present invention,and any amplifier can be converted to play the present instrument.

I claim:

In a musical instrument, a body member, a finger board extending fromsaid body member, a plurality of strings extending longitudinally alongthe top surface of said finger board and said strings adapted to bemanually pressed downward, a tailpiece having said strings groundedthereto, a cable jack electrically connected to said finger board, saidfinger board being made of a non-conducting material, there being aplurality of longitudinally extending grooves in said finger board, aplurality of frets extending upwardly from said finger board and adaptedto be contacted by said strings, securing elements for holding saidfrets in place on said finger board and said securing elements includingheads seated in said grooves, a plurality of resistors positioned incertain of said grooves, wires connecting said resistors in series tocertain of said frets, said grooves being defined by wall sections, eachof said wall sections being provided with cutouts, said fretscorresponding to musical notes, and jumper wires extending through saidcutouts and connecting similar notes together.

References Cited in the file of this patent UNITED STATES PATENTS1,847,119 Lertes Mar. 1, 1932 2,070,344 Waters Feb. 9, 1937 2,528,663Mitchell Nov. 7, 1950

